Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology Revision 🌱 > Chapter 13 > Flashcards

Chapter 13 Flashcards

1
Q

what are the two types of reproduction?

A

sexual and asexual

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

how many parents in asexual?

A

1

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

how do cells divide in asexual reproduction?

A

mitosis (a cell divides in two to make new ones)

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

what is important to remember about the offspring of asexual reproduction?

A

they will be genetically identical to the parent

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

why will the offspring of asexual reproduction be genetically identical to the parent?

A

no fusion of gametes - the genetic information in the offspring will be identical to the parent

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

another name for the offspring of asexual reproduction?

A

clones

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

where is asexual reproduction most common? 4

A

bacteria
some plants and animals
human body cells

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

how many parents are involved in sexual reproduction?

A

2

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

what are the sex cells called?

A

gametes

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

what do the two sex cells fuse to form?

A

a zygote

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

how are gametes formed?

A

meiosis

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

what is important to remember about sex cells?

A

they have half the number of chromosomes so the zygote will have the correct number

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

how many chromosomes in a sperm or egg cell?

A

23

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

what is important to remember about the offspring of sexual reproduction?

A

they won’t be identical to the parents - variation

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

sex cells in plants

A

egg cells and pollen

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

why is variation important?

A

it allows variation in the offspring to adapt to changes in the surroundings

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

in humans, where does meiosis take place?

A

testes and ovaries

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

what does meiosis result in?

A

sex cells (gametes)

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

how many cell divisions are involved in meiosis?

A

2

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

why is there variation in offspring produced by sexual reproduction?

A

each gamete is different, and then this different gamete fuses with another gamete that is different to the parent, making more variation

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

process of meiosis

A
  1. the cell duplicates its genetic information (chromosomes) so there are 4 sets rather than the normal 2
  2. the cell then quickly divides twice to form 4 gametes each with a single set of chromosomes in
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

advantages of asexual reproduction

A

only one parent needed

uses less energy because no mate is needed - faster

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

advantages of sexual reproduction

A

variation

natural selection - better adapted animals pass on the genes needed for successful survival in this habitat

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

most common method of reproduction in fungi

A

asexual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
name 3 examples of both asexual and sexual reproduction
plants malaria parasite fungi
26
how do fungi use both types of reproduction to their advantage?
they produce asexually when conditions for them are good and they have the adaptions needed to survive then reproduce sexually when conditions are bad and they need to adapt to survive
27
what is the disease called where a baby has extra fingers or toes?
polydactly
28
is polydactly dominant or recessive?
most commonly dominant
29
what is a punnet square?
a diagram that shows you the predicted outcomes of the children with certain diseases
30
what are the sex chromosomes of females?
XX
31
what are the sex chromosomes of males?
XY
32
how do malaria parasites reproduce both sexually and asexually?
in their host (the human) they will reproduce asexually to create lots of clones in the mosquito, they will produce sexually to encourage variation as the mosquito is a lot cooler than the human and they need to be able to survive they will then reproduce asexually in the mosquito to make as many parasites as possible
33
2 examples of asexual reproduction in plants
strawberry plants sprouting from runners | daffodils from bulbs
34
how do plants use sexual reproduction?
pollination - an insect carries pollen from one flower to another, creating new plants via sexual reproduction
35
what are the sex organs on a plant?
the flowers
36
what does DNA stand for?
deoxyribonucleic acid
37
what does DNA determine?
what characteristics you have
38
shape of DNA
double helix
39
what type of structure is DNA?
a polymer
40
what is a gene?
a small section of DNA found on a chromosome
41
how many different amino acids are used?
20
42
what does a gene do?
tells the cells what order to put the amino acids together in
43
what is the genome?
the entire set of genetic material in an organism
44
why do we need to understand the genome? 3
we can identify genes that cause different diseases we can then develop better treatments for them we can trace the migration of certain groups from around the world
45
how many genes are in the human genome?
21,000
46
what is DNA made from?
alternating phosphate and sugar sections
47
what is a nucleotide?
a combination of a sugar, phosphate and base
48
what are the four bases?
A, C, G, T
49
what are the nucleotides grouped in?
3s
50
what forms the backbone of the strand? (the single coloured section around the edge of the helix?
the phosphate and the sugar
51
what does an A always pair with?
a T
52
what does a C always pair with?
a G
53
what can the non-coding part of DNA do?
turn genes on and off
54
what is a mutation?
a random change in an organism's DNA
55
what is a phenotype?
physical expression of a gene combination
56
what do mutations do?
change the sequence of DNA bases in a gene, so the protein it produces isn't always correct
57
2 serious impacts of mutations on proteins
the shape of an enzyme's active site could change | structural proteins could lose their strength
58
3 types of mutations
insertion deletion substitution
59
how does insertion work?
a new base is inserted into the DNA sequence where it shouldn't be
60
how does deletion work?
a random base is deleted from the DNA sequence
61
how does substitution work?
random bases in the DNA base sequence are changed for another base
62
what is an allele?
a different form of a gene
63
what is a homozygote?
an individual with 2 identical alleles for a characteristic, eg BB or bb
64
what is a heterozygote?
an individual with 2 different alleles for a characteristic , eg Bb
65
what is a genotype?
the genetic make up of an individual regarding a single characteristic
66
what is a dominant allele?
the allele that overrules the recessive allele to show the characteristic in the person
67
what must happen for an organism to display a recessive characteristic?
both of its alleles must be the same (bb)
68
what is a genetic diagram?
models used to show all the possible expected genetic outcomes
69
what are most characteristics a result of?
several genes interacting
70
best diagram to show genetic outcomes?
Punnett square
71
what to remember about showing a Punnett square in an exam?
write out all the possible outcomes, what they show and the probability (eg, black fur, 50%, BB)
72
what do all human eggs contain?
an X chromosome
73
what is cystic fibrosis?
when the body produces lots of thick, sticky mucus especially in the lungs
74
which type of allele is cystic fibrosis caused by?
a recessive allele
75
3 treatments for cystic fibrosis
physiotherapy antibiotics enzymes to replace ones the pancreas can't secrete
76
effect of cystic fibrosis on pancreas
the pancreas becomes clogged up and can't secrete enzymes
77
what is a carrier?
a person who is healthy but carries the recessive allele
78
why must two people who are carriers create a child with cystic fibrosis?
it is a recessive allele
79
how many people in the UK carry the cystic fibrosis allele?
4%
80
what is genetic engineering?
when scientists replace faulty genes that cause a disorder with healthy ones
81
when is amniocentesis carried out?
15-16 weeks
82
process of amniocentesis
a needle is inserted into the amniotic sack, fluid is sucked up and then analysed
83
main three ways of harvesting cells from embryos
amniocentesis chorionic villus sampling IVF
84
when is chorionic villus sampling carried out?
between 10-12 weeks
85
process of chorionic villus sampling
cells are taken from the developing placenta, either with a needle or catheter and then analysed
86
advantages of offering genetic testing to all pregnant couples 3
can identify potentially fatal diseases gives the parents the knowledge and option of what to do allows a couple using IVF to have the best chances at a healthy, surviving baby
87
disadvantages of offering genetic testing to all pregnant couples 3
expensive the parents are faced with a very difficult decision increased risk of miscarrying a healthy baby
88
what will meiosis result in?
non-identical cells being formed
89
what will mitosis result in?
identical cells being formed
90
where is meiosis used?
to create sex cells
91
process of meiosis
copies of genetic information are made cell quickly divides twice to form 4 sets of gametes these gametes have half the number of normal chromosomes
92
what is important to remember about all gametes
they are genetically different
93
what is an allele?
the different forms of a gene (i.e. dominant or recessive)
94
what do non-coding parts of DNA do?
switch genes on and off
95
process of protein synthesis?
DNA in the nucleus unravels enzymes make a copy of the DNA called mRNA mRNA travels from nucleus to ribosomes ribosomes translate 3 bases into amino acids ribosomes link amino acids to form a protein
96
what is mRNA and what does it do?
Messenger RNA | it is a copy of the DNA sent from the nucleus to the ribosomes to code for proteins
97
function of a gene?
it contains DNA | it codes for the production of a specific amino acid
98
How are seeds produced?
Pollination of egg cells in one flower by pollen from another
99
How are embryos screened for alleles that cause genetic disorders?
DNA isolated from embryo Fluorescent probe mixed with embryo DNA Probe binds to DNA UV light shows up alleles for disorder

Biology Revision 🌱 (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions