Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology, 5th Form > 3. Repriduction And Inheritance > Flashcards

3. Repriduction And Inheritance Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Does SEXUAL reproduction produce genetically identical or genetically varied offspring!?

A

. This produces genetically varied offspring using specialised cells called gametes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Does ASEXUAL reproduction produce genetically varied or genetically identical offspring

A

. This produces genetically identical offspring. Gametes are not needed and there is only one parent involved

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What advantages does SEXUAL reproduction pose !?

A

. This method is an advantage in a changing environment or when there is a threat of disease from pathogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What advantages does ASEXUAL reproduction pose!?

A

. The offspring, called CLONES, are at an advantage in a stable environment because it allows parent plants with advantageous adaptations to produce offspring with the same beneficial characteristics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

In order to FERTILISE a plant the male (pollen) and female (ovum) gametes must…

A

. … fuse, to form a single cell called a ZYGOTE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does a ZYGOTE transform into an embryo !?

A

. The zygote will divide many times by MITOSIS to form all the cells of the new organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where is the STAMEN of the INSECT pollinated flower located!?

A

. Enclosed within the flower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Where is the STAMEN in a WIND pollinated plant located !?

A

. Exposed, outside of petals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The STIGMA of an INSECT pollinated flower is…

A

. … Enclosed within the flower and sticky

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The STIGMA of a WIND pollinated flower is…

A

. … Exposed outside of petals, often, “feathery”.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What features to the PETALS of INSECT pollinated flowers obtain !?

A

. They are large and brightly coloured

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What features do the PETALS of INSECT pollinated obtain!?

A

. Small, usually green

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Do INSECT pollinated flowers have a NECTARY!?

A

. Present- produce sugary fluid to attract insects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Do WIND pollinated flowers have a NECTARY!?

A

. Absent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

POLLINATION: (Gap fill)
1. In plants pollen grains are deposited onto the ______!?

A

. In plants pollen grains are deposited onto the STIGMA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

POLLINATION:(gap fill)
2. The pollen grain normally grows a ______ ____ which grows down through the _____

A

. The pollen grain normally grows a POLLEN TUBE which grows down through the STYLE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

POLLINATION: (Gap fill)
3. _______ are secreted at the tip of the tube which digest the tissues of the style

A

. ENZYMES are secreted at the tip of the tube which digest the tissues of the style

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

POLLINATION: (gap fill)
4. When the tube reaches an ovule the male gamete travels through the tube entering the _____ through a small hole called the _________

A

. When the tube reaches an ovule the male gamete travels through the tube entering the OVULE through a small hole called the MICROPYLE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

POLLINATION:(gap fill)
5. It the fuses with the female gamete (____) in the process of _____________

A

. It the fuses with the female gamete (OVUM) in the process of FERTILISATION

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

POLLINATION:(gap fill)
6. The fertilised ovum divides by _______ to form the embryo

A

. The fertilised ovum divides by MITOSIS to form the embryo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

POLLINATION:(gap fill)
7. The ovule develops into the ____

A

. The ovule develops into the SEED

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

POLLINATION:(gap fill)
8. The ovary develops into the _____

A

. The ovary develops into the FRUIT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does the ZYGOTE become once the plant is fertilised !?

A

. The zygote develops into an embryonic plant with a small root (RADICLE) and shoot (PLUMULE)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does the OVULE WALL become once the plant is fertilised !?

A

. The ovule wall becomes the TESTA ( hard coating of the seed )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Practical: Investigating the conditions needed for seed germination

A

Cress seeds are added to cotton wool in test tubes.
- Tube A is put in a fridge (no warmth), the rest are kept on the windowsill
- Tube C, the cotton wool is moistened with boiled water and an oxygen absorber (sodium pyrogallol) is added (no oxygen)
- Tube E is wrapped in foil (no light)
- Tube B, the cotton wool is kept dry (no water)
- Tube D has all the conditions present

Check germination after 2-3 days, perhaps combine class results

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

During the Practical (investigating the conditions needed for germination) which seeds germinate !?

A

. Tube D, all conditions present

. Tube E, no light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How do germinating seeds obtain a great deal of energy quickly !?

A

. They use their food stores, using ENZYMES that break down carbohydrate stores

. These are then used as fuel in respiration to release energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

When does a seed stop using their food stores to obtain energy !?

A

. They used their food stores until the leaves are in a position to Photosynthesise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

In order to germinate plants need three things:

A

. Oxygen

. Warmth

. Water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Why does a seed need OXYGEN to germinate ?!

A

. To aerobically respire

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Why does a seed need WARMTH to germinate!?

A

. Optimum temperature for enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Why does a seed need WATER to germinate !?

A

. To activate the enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the FOOD STORE called in young, germinating, plants!?

A

. Cotyledons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

A plant can reproduce ASEXUALLY by RUNNERS, how do they work !?

A

. A new plant is produced where the runner touches the ground

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

A plant can reproduce ASEXUALLY by TUBERS, how do they work !?

A

. One plant can produce many tubers which can each grow many shoots which form new plants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is a TUBER !?

A

. Swollen underground stems containing lots of stored food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

A plant can reproduce ASEXUALLY by BULBS, how do they work!?

A

. A main shoot will grow out of the parent bulb and another will grow out of the side “daughter” bulb, forming two plants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is a BULB!?

A

. Underground buds with thick fleshy leaves containing stored food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is An ARTIFICIAL method to grow plants ASEXUALLY!?

A

. Cuttings
- A piece of a plants stem , with a few leaves attached, is cut from a healthy plant. This is planted in damp compost, where it will grow roots and develop into a new plant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is a NATURAL method of growing a plant ASEXUALLY !?

A

. Runners

. Tubers

. Bulbs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Are gametes diploids or haploids!?

A

. Gametes are haploids (23 chromosomes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Definition of FERTILISATION:

A

. Fertilisation is the FUSION of haploid male and female gametes, restoring the diploid number of chromosomes in the zygote

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Are all sperm cells and all egg cells genetically identical!?

A

. No, each sperm cell and each egg cell is genetically different due to the process that has created them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is an AMNION !?

A

. An amnion encloses the developing embryo. The amnion secretes a fluid called AMNIOTIC FLUID

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is the function of AMNIOTIC FLUID!?

A

. It protects the developing embryo against jolts and bumps (mechanical shocks), drying out, and temp. Fluctuations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What does the embryo become when it looks human !?

A

. a FOETUS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What are the adaptions of SPERM cells!?

A

. A tail- called a flagellum- allowing it to swim through the female reproductive system

. A HAPLOID nucleus- has half the number of normal chromosomes

. Many MITOCHONDRIA- to produce energy

. Enzymes in the head- to penetrate egg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is the role of OESTROGEN in the menstrual cycle !?

A

. Inhibits FSH production (stops another ovum from being matured)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Where is OESTROGEN secreted from !?

A

. (A follicle In the) Ovary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What is the target organ for OESTROGEN!?

A

. Pituitary gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What is the role of PROGESTERONE in the menstrual cycle !?

A

. FSH and LH inhibited

. Maintains the thickness of the uterus lining

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Where is PROGESTERONE secreted from !?

A

. Ovary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What organ does PROGESTERONE target !?

A

. Pituitary gland

. Uterus lining

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What is the role of FSH in the menstrual cycle !?

A

. Follicle develops and ovum matures

. Maturing follicles release Oestrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Where is FSH secreted from !?

A

. Pituitary gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What organ does FSH target !?

A

. Follicle In ovary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What is the role of LH in the menstrual cycle!?

A

. Ovulation- follicle In ovary releases mature ovum into the oviduct

. Reminding of follicle (on ovary) becomes corpus luteum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Where is LH secreted from!?

A

. Pituitary gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What organ does LH target !?

A

. Follicle in ovary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What is the role of the PLACENTA!?

A

. Connected by an umbilical chord, it develops from the embryo. The placenta anchors the embryo in the uterus

. It allows nutrients to move from the mother to the embryo

. It allows metabolic wastes to move from embryo to mother

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What nutrients does the placenta allows to be transferred from the mother to the embryo !? (Via diffusion)

A

. glucose, amino acids, salts and oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What metabolic waste does the placenta allows to be transferred from the embryo to the mother !? (Via diffusion)

A

. Carbon dioxide and urea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Secondary characteristics in GIRLS are controlled by what hormone !?

A

. Oestrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Secondary characteristics in BOYS are controlled by what hormone!?

A

. Testosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Secondary sexual characteristics in GIRLS:

A

. Voice deepens
. Menstrual cycle begins
. Pelvis broadens, preparing for labour + pregnancy
. Armpit and pubic hair growth
. Muscle development and fat deposits on breasts, hips and thighs
. Growth and development of genitalia
. Mood swings and acne

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Secondary sexual characteristics in BOYS:

A

. Voice breaks
. Sperm production begins
. Shoulder broaden
. Facial, armpit, body and pubic hair growth
. Greater muscle development
. Growth and development of genitalia
. Mood swings and acne

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What is MITOSIS!?

A

. Mitosis is a type of cell division in which a diploid body cell copies itself and finally divides into two identical diploid DAUGHTER CELLS.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What are DAUGHTER CELLS !?

A

. Daughter cells are clones of each other. Every base pair of their DNA is identical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What is the first step of MEIOSIS !?

A
  1. The parent cell grows
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

MEIOSIS: (gap fill)
2. The ___ __________ (is copied) to form two copies of each chromosome. These copies (__________) are joined together at a single point (the centromere)

A

. The DNA REPLICATES (is copied) to form two copies of each chromosome. These copies (CHROMATIDS) are joined together at a single point (the centromere)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

MEIOSIS: (gap fill)
3. The nuclear membrane breaks down. The _________ _____ __ ___________ ____ ________

A

. The nuclear membrane breaks down. The HOMOLOGOUS PAIRS OF CHROMOSOMES JOIN TOGETHER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

MEIOSIS: (gap fill)
4. The homologous pairs of chromosomes ________ ________ __ ___. Then attach to the spindle fibers in _____, at the centre of the cell

A

. The homologous pairs of chromosomes EXCHANGE SECTIONS OF DNA. Then attach to the spindle fibers in PAIRS, at the centre of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

MEIOSIS: (gap fill)
5. The _________ _____ __ ___________ are ______ _____ and move to opposite ends of the cell. The cell divides

A

. The HOMOLOGOUS PAIRS OF CHROMOSOMES are PULLED APART and move to opposite ends of the cell. The cell divides.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

MEIOSIS: (gap fill)
6. The chromosomes line up along the ______ of the cell, attached to the spindle fibers. The __________ ________ and move to _______ ends of the cell. Each cell divides again

A

. The chromosomes line up along the CENTRE of the cell, attached to the spindle fibers. The CHROMATIDS SEPARATE and move to OPPOSITE ends of the cell. Each cell divides again

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

How many cells does MITOSIS produce!?

A

. MITOSIS Produces two genetically identical daughter cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

How many cells does MEIOSIS produce!?

A

. MEIOSIS produces four genetically NON- identical daughter cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

How many cell divisions occur in MITOSIS!?

A

. Mitosis involves one division

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

How many cell divisions occur in MEIOSIS!?

A

. Meiosis involves two cell divisions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Does MITOSIS produce Haploid or diploid cells in humans!?

A

. Mitosis produces diploid cells in humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

Does MEIOSIS produce haploid or diploid cells in humans !?

A

. Meiosis produces haploid cells in humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

Where does MITOSIS occur in the human body !?

A

. Mitosis occurs throughout the human body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

When does MITOSIS occur !?

A

. During:
- growth and repair
- cloning
- asexual reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

What is MEIOSIS!?

A

. Meiosis is the type of cell division which gives rise to cells that are genetically DIFFERENT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

Where does MEIOSIS occur in the human body!?

A

. Meiosis takes place in the SEX ORGANS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

When does MEIOSIS occur!?

A

. During:
- only used to produce gametes
- sexual reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

Why, Due to MEIOSIS, is offspring genetically different from each other and their parents!?

A

. Meiosis produces four genetically different haploid cells. As a result of MEIOSIS and FERTILISATION, the maternal and paternal chromosomes meet in different combinations in the zygotes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

What is the first stage of MITOSIS!?

A

. The cell grows

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

MITOSIS: (gap fill)
2. The ___ __________ (is copied) to form two copies of each chromosome. These copies (_________) are joined together at a single point (the centromere

A

. The DNA REPLICATES (is copied) to form two copies of each chromosome. These copies (CHROMATIDS) are joined together at a single point (the centromere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

MITOSIS: (gap fill)
3. The nuclear membrane breaks down. The ___________ ____ __across the centre of the cell, attached to special _______ fibres

A

. The nuclear membrane breaks down. The CHROMOSOMES LINE UP across the centre of the cell, attached to special SPINDLE fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

MITOSIS: (gap fill)
4. The __________ (copies of chromosomes) are ______ _____ and move to opposite ends of the cell

A

. The CHROMATIDS (copies of chromosomes) are PULLED APART and move to opposite ends of the cell

91
Q

MITOSIS: (gap fill)
5. The ________ and ____ ________ _______ to form two identical cells

A

. The CYTOPLASM AND CELL MEMBRANE DIVIDES to form two identical cells

92
Q

How may chromosomes in a DIPLOID!?

A

. 46

93
Q

How many chromosomes in a HAPLOID !?

A

. 23

94
Q

Insect or wind pollinated !?

A

Insect pollinated

95
Q

Insect or wind pollinated !?

A

Wind pollinated

96
Q

What is the genome !?

A

The Genome is the entire DNA of an organism

97
Q

What is a gene !?

A

A gene is a section of a molecule of DNA that codes for a specific protein

98
Q

Where are genes located !?

A

The nucleus of a cell contains chromosomes on which genes are located

99
Q

On what does a gene provide genetic information!?

A

It provides information on the sequence of amino acids in a protein (e.g. an enzyme)

100
Q

What do the proteins coded for by a gene control !?

A

These proteins, then control, chemical reactions, growth, coloration, or inheritable characteristics

(E.g. the height of a pea plant, or the colour of eyes)

101
Q

Is the code produced by genes selective or universal !?

A

The code is a universal. Bacteria, read it in the same way that animals and plant cells read it.

102
Q

Within DNA what codes for a specific amino acid !?

A

In DNA, the sequence of three bases, codes for a specific amino acids

(E.g. the sequence TAG. Would code for one amino acid whereas CCG would code for a different amino acid in the chain of amino acids, making up the protein.)

103
Q

What is a codon!?

A

We refer to every three bases as a codon
E.g. TAG or CCG

104
Q

Why is DNA wrapped into chromosomes!?

A

Because the DNA is enormously long, it is wrapped up in structures called chromosomes

105
Q

How many chromosomes does each person have !?

A

Each person has two of each chromosome.

(One of each pair comes from the father, the other from the mother.)

106
Q

Why are chromosomes homologous !?

A

Genes, controlling specific characteristics are situated at the same point on each Chromosome, (so we say the chromosomes are homologous)

107
Q

What is a genome!?

A

A genome is the entire genetic information of an organism

(the amount present in a diploid cell)

108
Q

Name the bases:

A

Adenine
Thymine

Guanine
Cytosine

109
Q

Describe the structure of DNA :

A

. Double stranded

. Coiled into helix

. Sugar phosphate backbone

. Polymer made up of nucleotides

. Complementary base pairing

110
Q

Which animal cell doesn’t contain a nucleus !?

A

Red blood cell

111
Q

What is the role of the nucleus !?

A

The role of the nucleus is to control the activities of the cell, using the genes

112
Q

Where is genetic information stored within the nucleus !?

A

The nucleus contains the genetic information needed to produce a new cell. This information is stored on chromosomes

113
Q

Label:

A
114
Q

How many autosomes are there in humans !?

A

In humans of the 23 pairs of chromosomes, 22 pairs are called autosomes

115
Q

What is the 23 pair of chromosome in humans !?

A

The 23rd pair are the sex chromosomes, and these determine the sex of the individual

116
Q

How many matching pairs of chromosomes do males have !?

A

The cell from the male has 22 chromosomes that pair up and two that do not form a matching pair X and Y chromosomes

117
Q

How many matching pairs of chromosomes do females have !?

A

A body cell from the female has 23 matching pairs, including X chromosomes

118
Q

What are pairs of matching chromosomes Called !?

A

Pairs of matching chromosomes are called homologous pairs

119
Q

What do homologous pairs of chromosomes consist of !?

A

Homologous pairs carry genes for the same features, and these genes are arranged in the same position and sequence along the chromosome

120
Q

What is the locus !?

A

The position of the gene within a chromosome

121
Q

What are histones!?

A

Histones are structural proteins that hold the long molecule of DNA within a chromosome in place

122
Q

By what process does DNA replicate itself !?

A

DNA can replicate itself during mitosis

(every cell except egg and sperm cells)

Each new cell or receive exactly the same type and amount of DNA- they are genetically identical

123
Q

What is the role of the gene !?

A

Genes instruct cells to produce a particular protein, which then leads to the development of features

124
Q

What is the definition of an allele!?

A

Different versions of genes

125
Q

An example of when chromosomes carry genes for the same features, but in a different Locus:

A

The version of a gene on one chromosome may code for brown eyes. Whereas the version of the gene on the other chromosome a code for blue eyes

126
Q

How do alleles arise !?

A

Alleles arise because of mutations

127
Q

Are both features expressed if you have two different alleles!?

A

Not both features are expressed if you have two different alleles e.g. brown hair, blonde hair. This is because one of the alleles is dominant and one is recessive.

128
Q

Definition of a dominant allele:

A

A dominant allele only needs one allele present to be expressed and will show its effect

129
Q

Definition of a recessive allele:

A

A recessive allele needs two alleles present to be expressed, and will only show up in the appearance of the person if there is no dominant allele present

130
Q

Definition of a codominant allele:

A

A co-dominant allele will affect the phenotype equally in the presence of another co-dominant allele (both of alleles have capital letters)

131
Q

Who worked out the chemical structure of DNA in 1953!?

A

James Watson and Francis crick

132
Q

What did James Watson and Francis crick work out about the chemical structure of the DNA?

A

. DNA consists of two polynucleotide strands.

. The two strand coil round each other in a double helix.

. The backbone is a sugar-phosphate arrangement

. The bases project was the inside of the double helix.

. DNA is wrapped around a histone.

133
Q

What is the name of the two strands of molecules that make up DNA !?

A

Nucleotides

134
Q

What does each nucleotide contain !?

A

Each nucleotide contains a sugar molecule (deoxyribose) a phosphate group, and a nitrogenous base containing group called a base

135
Q

When the four bases complimentary base pair, what is the bond between them made from?

A

They are called hydrogen bonds

136
Q

What do nucleotides form when they join together !?

A

Individual nucleotides join together to form a polynucleotide, bonds form between sugar and the phosphate molecules

137
Q

What is the bond between the sugar and the phosphate molecules called that joins two nucleotides together to form a polynucleotide!?

A

A Phosphodiester bond

138
Q

Question: there are 240 bases, 70 are thymine, calculate the number of each other base.

A

T = 70
A = 70
G = 50
C = 50

139
Q

What are the environmental factors that can affect the characteristics of species?

A

Climate,
diet,
culture,
lifestyle,
and accidents during lifetime

140
Q

What do environmental factors that can affect the characteristics of species mean?

A

In this instance, ‘environmental’ sympathy means outside of the organism

141
Q

Why do continuous features often vary !?

A

Continuous features often vary because of a combination of genetic and environmental causes

142
Q

Definition of a cell:

A

The basic structural unit of living organisms

143
Q

Definition of a nucleus:

A

Cell organelle that contains chromosomes or genetic information that controls the activities of the cell

144
Q

Definition of a chromosome:

A

. Made of DNA
. genes located on
. found in the nucleus

145
Q

Definition of a gene:

A

Section of molecule of DNA coding for a specific protein

146
Q

Definition of a genome:

A

The entire DNA of an organism (present in a diploid cell)

147
Q

Definition of a diploid:

A

Number of chromosomes found in body cells, both chromosomes of homologous pair

148
Q

Definition of a haploid:

A

Number of chromosomes found in gametes

149
Q

Definition of an allele:

A

Different forms of the same gene

150
Q

Definition of a dominant:

A

Allele of gene that is expressed

151
Q

Definition of a recessive:

A

Allele that is not expressed in phenotype, when dominant allele is present

152
Q

Definition of a co-dominant:

A

Pattern of inheritance were neither allele of the gene is dominant over the other type, so both alleles are expressed in the phenotype

153
Q

When does mitosis occur !?

A

Mitosis occurs during growth, repair, cloning, and asexual reproduction
- identical
(my toe GROWS)

154
Q

What is the definition of variation!?

A

Variation is defined as differences between individuals of the same species

155
Q

What are the three causes of variation in humans !?

A

. Genetic
. Environmental
. Combination of both

156
Q

What is a phenotype!?

A

Phenotype is a particular version of a characteristic seen in an individual

157
Q

What is phenotypic variation !?

A

Phenotypic variation is variability in the phenotype that exists in a population as a result of your genetic variation and environmental factors

158
Q

What is genetic variation caused by!?

A

Genetic variation is controlled entirely by genes

159
Q

What is environmental variation caused by!?

A

Environmental variation is caused entirely by the environment in which the organism lives

160
Q

What process produced the genetic variation between the gametes!?

A

Meiosis creates genetic variation between the gametes produced by an individual

(this means each gamete carries substantially different alleles)

161
Q

During fertilisation what does the fusion of the male and female gamete form !?

A

During fertilisation, any male gamete, can fuse with any female gamete to form a zygote

162
Q

What did the random fusion of gametes at fertilisation create !?

A

This random fusion of gametes at fertilisation creates genetic variation between zygote, as each will have a unique combination of alleles

163
Q

Examples of genetic variation in humans:

A

. Blood group
. Eye colour
. Gender

164
Q

Examples of continuous variation:

(combination of environmental and genetic causes)

A

Tall parents will pass genes to their children for height.

The children have the genetic potential to also be tall.

However, if their diet is poor they won’t grow very well

therefore the environment also has an impact on their height.

165
Q

Relationship between genetic and environmental causes:

A

Although the genes decide what characteristics we inherit, the surrounding environment will affect how these inherited characteristics develop

166
Q

What is continuous variation !?

A

Continuous variation is when there are very many small degrees of difference for a particular characteristic between the individuals,

(and they are arranged in order and can be usually measured on a scale)

167
Q

Examples of continuous variation :

A

Height

mass

finger length

168
Q

What causes continuous variation !?

A

Continuous variation is due to the combined effects of both environmental and inherited factors

169
Q

How do we display continuous variation on a graph!?

A

We display this data using a bar chart with a line of best fit. This usually gives a smooth bell curve because of the small degrees of difference

170
Q

What is discontinuous variation !?

A

Discontinuous variation is when there are distinct differences for a characteristic

171
Q

Examples of discontinuous variation:

A

Blood group

Eye colour

gender

roll their tongue
(there are no in-betweens)

172
Q

How do we display discontinuous variation on a graph!?

A

We display this data using a bar chart. This usually gives a step like shape.

173
Q

What is polygenic inheritance?

A

Polygenic inheritance are characteristics that are controlled by more than one gene, which influence each other.

174
Q

Most phenotypic features, a result of _________ ___________rather than _____ _____ (fill)

A

Most phenotypic features are a result of polygenic inheritance, rather than single genes

175
Q

What is are homozygous chromosomes !?

A

If the alleles for a characteristic in a homologous pair are the same, the organism is homozygous for that characteristic

176
Q

What is are heterozygous chromosomes !?

A

If the alleles for a characteristic of a homologous pair are different, the organism is heterozygous

177
Q

For heterozygous alleles how do we know which characteristic will be expressed !?

A

The characteristic expressed by heterozygous alleles, will depend on which allele is dominant and which allele is recessive

178
Q

What does the phenotype for a particular characteristic depend on !?

A

The phenotype for a particular characteristic depends on which allele is dominant, and which recessive

179
Q

Definition of genotype:

A

Alleles that an organism possesses for a certain characteristic
E.g. BB (homozygous dominant)
bb (homozygous recessive)

180
Q

Definition of phenotype:

A

Physical appearance of an organism resulting from the genotype

181
Q

What are monohybrid crosses !?

A

Monohybrid crosses are crosses with only one different trait

182
Q

Definition of an allele:

A

Different forms of the same gene

183
Q

Monohybrid genetic crosses:

A

Phenotype of parents

Genotype of parents

Gametes

Genotype F1

Phenotype F1

Gametes F1 organism

Genotype F2

Phenotype F2

184
Q

What does F1 stand for !?

A

Offspring formed by parent

185
Q

What does F2 stand for !?

A

Offspring formed when we cross F1 generation

186
Q

Question: cross adominant, homozygous Browne eyed mother, with a recessive, homozygous blue eyed father:

A
187
Q

How many pairs of chromosomes do humans have?

A

Humans have 23 pairs of chromosomes

188
Q

Which pair of chromosomes determines the gender of the human being !?

A

The 23rd pair of chromosomes determines the gender of the human being

189
Q

What is always a female’s 23rd pair of chromosome !?

A

Females will always have XX as their pair of 23rd chromosomes

190
Q

What is always a male’s 23rd pair of chromosome !?

A

Males will always have XY is there a pair of 23rd chromosomes

191
Q

What is the likelihood of having a boy or a girl?

A

The likelihood of having a boy or a girl is 50-50, and is proved with the below genetic diagrams

192
Q

Examples of polygenic inheritance:

A

Human skin colour.

Height

Body mass

193
Q

Why are there so many different human skin colours?

A

Because the amount of melanin in the skin is controlled by several genes. Each gene has alleles that promote melanin production and alleles, which do not this produces a wide range of phenotypes.

194
Q

What happens before a cell divides !?

A

Before a cell divides, the chromosomes replicate making an exact copy of themselves. This doubles amount of DNA in the cell.

195
Q

Describe the products of mitosis:

A

Mitosis produces genetically identical daughter cells. The cells are diploid. They have one pair of each chromosome in each nucleus.

196
Q

What is mitosis used for !?

A

Mitosis is used for growth,repair and asexual reproduction

197
Q

Describe the products of meiosis:

A

Meiosis produces haploid gametes (sperm, eggs, pollen), which are not genetically identical

198
Q

What is meiosis used for !?

A

Meiosis is only used to produce gametes for sexual reproduction

199
Q

What is a consequence of meiosis !?
(genetic variation)

A

A consequence of meiosis is that every gamete produced is genetically different

200
Q

Why is every gamete produced by meiosis genetically different !?

A

This is because it contains different combinations of chromosomes from that persons, mother and father

201
Q

What are the two ways variation in offspring occurs !?

A

. Genetic variation in gametes produced by meiosis

. Random fertilisation of ova by male gametes

202
Q

What do we often determine from family trees !?

A

Afton family trees can be used to determine the probability of inheriting a genetic disease

203
Q

Definition of a pedigree diagram:

A

A pedigree diagram is a family history for an inherited genetic condition

204
Q

How could we work out if the disease was dominant or recessive !?

A

Use F, C and H is the example the parents are not affected, but had an infected daughter. The daughter must have inherited one allele from each parent.

If the disease was dominant and the parents had just one copy of the faulty allele, they would be affected however another parent is but they still had an infected daughter. Therefore the disease is recessive

205
Q

How can we tell the genotype of F and C !?

A

We can also tell the genotype of F and C. This is because the parents must be heterozygous and contain one normal allele and one faulty allele. They must’ve passed on a faulty allele to their daughter, but do not exhibit the disease so much have one normal allele

206
Q

Definition of a mutation

A

A mutation is a change in the sequence of bases in DNA

207
Q

What are the three different types of mutation!?

A

Replacement of a single base pair with a different pair

In addition or deletion of one or more base pairs

Chromosomal mutation

208
Q

What is the result of replacement or an addition or deletion mutation!?

A

It gives a change in the DNA sequence, which intern changes the sequence of amino acids in a protein. This will normally alter the shape and function of the protein.

209
Q

Are mutations common or rare!?

A

Mutations are comparatively rare events in eukaryotes as our cells can detect incorrect many mistakes in the DNA sequence

210
Q

Why are changes in the DNA sequence often neutral!?

A

As mutation doesn’t take place on active site

211
Q

When is a mutation inherited!?

A

If the mutation occurs during meiosis in gamete formation, it will affect all of the cells in the individual which develops from the gametes. This means the mutation is inherited

212
Q

When is a mutation not inherited!?

A

If the mutation occurs in a body cell, it will affect only those cells produced by mitosis from the effected cell. Mutations in body cells give rise to cancers of the cells that are affected. This type of mutation is not inherited.

213
Q

What are mutagens !?

A

Mutations are chemicals which cause more frequent mutations

214
Q

Examples of mutagens:

A

. Ionising radiations(x and gamma ray, ultraviolet light)

. and some chemicals e.g. in tobacco

215
Q

Do mutations increase or decrease genetic variation in a population!?

A

Mutations increase genetic variation in a population

216
Q

An example of a mutation:

A

Blue eyes (originally brown)

217
Q

What observations was Darwin’s theory of evolution based on !?

A

. All living things organisms show variation

. All living things tend to over-reproduce

218
Q

Why will there be a struggle for existence according to Darwin’s ‘survival of the fittest’ theory?!

A

There will be a “struggle for existence” because organisms over reproduce, and therefore resources will be limited

219
Q

Why are there organisms better adapted to their environment than others according to Darwin’s ‘survival of the fittest’ theory?!

A

Some organisms will be better adapted to their environment than others because they vary

220
Q

What happens to the best adapted according to Darwin’s survival of the fittest theory?

A

The best adapted will survive and reproduce in greater numbers than the less well adapted

221
Q

Modern interpretation of Darwin’s survival of the fittest theory:

A
222
Q

What are antibiotics !?

A

Antibiotics are chemicals that kill bacteria and do not usually harm animal cells

223
Q

How do antibiotics kill bacteria only !?

A

The achieve this by targeting cell structures, such as bacterial cell walls, which animal cells do not contain

224
Q

How has natural selection lead to the antibiotic resistance of penicillin !?

A

Biology, 5th Form (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions