Biology: Genetics Flashcards
1
Q
what is the function of reproduction?
A
the passing on of duplicated DNA from one generation to the next.
2
Q
what is the function of the ovary
A
to produce and release egg cells (ovum) in preparation for a possible pregnancy
3
Q
what is the function of vagina
A
a muscular canal that acts as a passageway for sperm to get to the uterus
4
Q
what is the function of uterus
A
a hollow, muscular organ that nourishes a foetus prior to birth
5
Q
what is the function of fallopian tube
(2 pts)
A
- it is a passageway for the ovum to get to the uterus. muscle contractions and cilia (tiny hairs) move the ovum along
- it is also where the sperm and ovum would meet
6
Q
what is the function of the cervix (2 pts)
A
- an opening to the uterus from the vagina
- dilates during labour to make way for a baby
7
Q
what is the function of the testes
A
where sperm cells are produced
8
Q
what is the function of the vas deferens
A
a long tube that connects the epididymis to the urethra
9
Q
what is the function of prostate gland
A
secretes alkaline fluid that neutralizes acids in female reproductive system
10
Q
what is the endometrium?
(3 pts)
A
- the endometrium is the inner lining of the uterus.
- the endometrium grows and thickens in response to hormones throughout the menstrual cycle.
- on day one of the menstrual cycle, the endometrium will shed if a fertilised egg has not been embedded in it.
11
Q
define gamete
A
a reproductive cell for plants and animals, informally known as a sex cell
12
Q
define sperm
A
a male reproductive cell produced in the testes
13
Q
define ovum
A
a female reproductive cell produced in the ovaries
14
Q
define fertilisation
A
the process of combining a female gamete, an ovum, with a male gamete, a sperm, to form a zygote
15
Q
define zygote
A
a combination of a female and male gamete; a fertilised ovum
16
Q
define foetus
A
an unborn offspring that develops and grows in the uterus
17
Q
what is the function of the seminal vesicles
A
produce a fluid rich in sugars that sperm use for energy
this fluid + prostate fluid combines with sperm cells to make semen
18
Q
what is the function of the urethra
A
semen and urine exit via the urethra
19
Q
what is the function of the scrotum
A
protect the testes, and control the temp the sperm is kept at.
20
Q
what is the function of the penis
A
deposits sperm in female reproductive system during sexual activity
21
Q
what is the function of the epididymis
A
after sperm production, sperm travel to the epididymis to mature
22
Q
where do offspring get their DNA?
A
from both parents
23
Q
what are chromosomes made up of?
A
DNA
24
Q
Define genes?
A
a section of DNA that code for a particular trait
25
what is DNA made up of?
nucleotides
26
in chromosomes, what is the DNA wound around?
the DNA is tightly wound around a protein called a histone
27
where is DNA found?
in the nucleus of every cell
28
how many chromosomes are in each cell for humans?
46 (23 from mum, 23 from dad)
29
what is a nucleotide made up of?
a sugar, a phosphate, and a nitrogenous base
30
what are the four nitrogenous bases in DNA?
1) Adenine
2) Thymine
3) Cytosine
4) Guanine
31
what is the complementary pairing of nitrogenous bases?
Adenine > thymine
Cytosine > Guanine
32
what is the name of the sugar in double helixs?
deoxyribose sugar
33
define chromosomes
long, paired, threadlike structure within a cell nucleus that are composed of genes
34
define DNA
an acid that carries information to determine an organism's traits–it is compacted in chromosomes and is present in every cell of a living organism.
35
define karyotype
shows a complete, visual set of an organism's genes
36
define variation
variation is the difference that exists between organisms. It occurs in any species.
37
what are the 2 types of variation + examples
1) discontinuous (discrete) variation, e.g eye colour, hair colour, blood type, sex
2) continuous variation
e.g weight, height, milk yield
38
what are the two factors that cause variation
genetics and environment.
39
what is inherited variation
inherited variation refer to differences in traits that you receive due to the genetic code your parents passed down to you, e.g eye colour
40
what is environmental variation
environmental variation refers to the variation in traits due to differing surroundings of an organism. in the sense of humans, this could be changes of lifestyle, culture, climate, diet etc.
41
what are the two shapes of base shapes?
single ring and double ring
42
define double helix
two linked strands that wind around each other to resemble a twisted ladder in a helix-like shape
43
define nucleotide
the building blocks of DNA, consisting of a phosphate, a deoxyribose sugar, and a nitrogenous base
44
define complementary base pairing
CBP refers to the way in which nitrogenous bases in DNA pair with each other in a consistent way, this being A+T and C+G.
45
what did watson and crick discover?
the structure of dna IS A DOUBLE HELIX.
46
define a haploid
a half set of chromosomes
47
define a diploid
a full set of chromosomes
48
define a genotype
the genes an organism has
49
define a phenotype
the physical appearance of an organism
50
define an allele
variations of a gene
51
define a homozygous allele
having the same alleles for a patricular trait
52
What does it mean to be heterozygous for an allele?
It means you have 2 different alleles for a particular trait, one being dominant and the other being recessive
53
define mitosis
mitosis is a process that occurs when the body needs to make new cells for growth or repair. A cell will divide and an identical copy of itself will be created
54
define meiosis
a form of cell division to make sex cells, ie sperm or ova
55
what are the four steps for cell replication
1. dna double helix untwists
2. an enzyme breaks the bonds between the base strands and the DNA becomes 2 separate strands
3. free nucleotides in the nucleus are attracted to their complementary bases
4. once nucleotides are lined up they are bonded by another enzyme
56
what is the name of the enzyme that acts as a molecular glue to keep nucleotides together
ligase
57
what is the enzyme that facilitates the movement of free nucleotides
polymerase
58
define mutation
a permanent change in an organism's DNA sequence
59
what are the two types of genetic mutation?
* gene
* chromosome
60
define meosis
the process where gametes are produced through cell division
61
how many stages of cell division does mitosis and meosis have?
mitosis has one stage
meosis has 2
62
why does mitosis occur (3 pts)
* living things grow by producing more cells
* to repair damaged tissue
* if a cell gets too big, it cannot get enough nutrients into the cell and waste out of the cell
63
what is a somatic cell
a body cell
64
what is a gamatic cell
a sex cell
65
what is loose DNA in the nucleus called?
chromatin
66
what is a chromatid
chromatin wound around a special protein called a histone
67
what is the part that joins two chromatids?
centomere
68
what are the 5 phases of mitosis?
1. interphase
2. prophase
3. metaphase
4. anaphase
5. telophase
69
what happens in interphase
the DNA in the parent cell replicates to form 2 copies of each chromosome
70
what happens in prophase
chromosomes condense to make themselves more visible, and membrane around the nucleus dissapears
71
what happens in metaphase
the chromosomes align at the equator of the cell
72
what happens in anaphase
sister chromatids are pulled apart to the poles of the cell
73
what happens in telophase
a new nuclear membrane forms around each set of chromosomes
74
what happens in cytokinesis
the cytoplasm and cell membrane divide to form two identical daughter cells
75
what is the overall cycle of cell division?
interphase > mitosis (PMAT) > cytokinesis > back to interphase
76
what are mutagens + 3 examples
mutagens are chemicals that cause mutations, e.g uv, radiation exposure, nicotine
77
how does a gene change result in a phenotype change?
when a gene changes, the resulting protein that codes for a particular characteristic is also changed, therfore affecting the look/functioning of an organism
78
what are chromosome vs gene mutations?
gene mutations are single gene changes, whereas chromosome mutations refer to a change across the entire chromosome
79
what is a stem cell?
stem cells are undifferentiated cells that have the potential to become specialised cells, e.g nerve / muscle cells
80
how are stem cells used to treat diseases in general?
isolated stem cells can be cloned in laboratories, and this can be used to replace damaged cells. this, in turn, can be used to treat and cure diseases
81
how are stem cells used to treat leukemia?
Leukemia affects blood cells, causing them to grow abnormally. Stem cell transplants (usually from bone marrow or umbilical cord blood) can replace the damaged blood cells with healthy ones, helping the body produce normal blood again.
82
how are stem cells used to treat burns and scarring?
Stem cells can help regrow damaged skin. Doctors can use special stem cells from the patient’s own body or from donors to create new skin layers, helping burn victims heal faster with less scarring.
83
how are stem cells being researched for parkinsons disease?
This disease happens when brain cells that make dopamine (a chemical that helps control movement) die. Scientists are researching how stem cells can be turned into new dopamine-producing brain cells to replace the lost ones and reduce symptoms like shaking and stiffness.
84
what are 3 practical limitations of stem cells
* adult stem cells are only reliable to differentiate into blood cells, therefore limiting treatment to diseases such as leukaemia, lymphoma etc.
* sometimes stem cells are registered as foreign objects by the body's immune system and therefore attacked
* viral contamination can occur to stem cells being grown, which can transfer to the patient if proper care is not taken in laboratories
85
what are embryonic stem cells
found in the early days of the human embryo that can differentiate into any type of cell
86
what are adult stem cells
few cells that can differentiate once an organism is fully developed, and they're found in small numbers in adult tissue.
87
what are ethical considerations of using embryonic stem cells?
extracting cells from an embryo and therefore destroying it is destroying an individual's potential for life
88
what are 2 non-invasive methods to gain embryonic stem cells?
using embryos left over from IVF treatment, and using embryonic cells from umbilical cord blood
89
what kind of diseases could stem cell research treat?
Neurodegenerative diseases like Alzheimer's and Parkinson's
* Spinal cord injuries resulting in paralysis
* Cardiovascular diseases
* Type 1 diabetes
* Rheumatoid arthritis
90
what are the 2 causes of mutations?
genetic and environmental
91
what is the subheading under environmental mutation?
Mutagens
92
what are the subheadings under environmental mutation?
mutagens
93
what is the subheading beneath genetic mutations?
gene and chromosomal
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94
what are the subheadings underneath gene mutation
point and frame shift
95
what is point mutation?
where one nitrogenous base is changed
96
what is frame shift mutation?
where either 1 nitrogenous base is deleted, or one is inserted (deletion, insertion)
97
if gene mutation occurs in ____ cells, then your children won't inherit it.
somatic
98
what is the name of acid in DNA?
deoxyribonucleic acid
