Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

SHHS - Science - AQA Biology Trilogy > 4.6 Reproduction TRIPLE > Flashcards

4.6 Reproduction TRIPLE Flashcards

(95 cards)

Start Studying
1
Q

A cell divides in a series of stages called

A

the cell cycle

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

What are the initial steps in the cell cycle?

A

The cell grows and organelle numbers increase, DNA replicates.

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

In the cell cycle after the DNA has replicated what happens next?

A

The copied chromosomes separate (mitosis) and then the cell divides into two.

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

What are the 2 forms of reproduction?

A

Asexual and sexual

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

Why is asexual reproduction important?

A

growth and repair

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

How many parents are involved in asexual reproduction?

A

1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
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
8
Q

Which form of reproduction involves gametes?

A

sexual - fusion of egg and sperm

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

Which form of reproduction brings about variation?

A

sexual

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

Name an organism that reproduces asexually

A

bacteria, daffodil bulbs, strawberry tubers

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

Name an organism what reproduces sexually

A

humans

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

What form of cell division produces gametes?

A

Meiosis

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

Where does meiosis occur?

A

testes and ovaries

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

Where does mitosis occur?

A

in all body cells except testes and ovaries

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

In plants what are the sex cells?

A

pollen and egg cell

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

In animals what are the sex cells?

A

egg cell and sperm

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

What is another name for a gamete?

A

sex cell

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

Why does sexual reproduction bring about variation

A

Involves FUSION of egg and sperm, creating a unique combination of alleles

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

Give an advantage of sexual reproduction

A

produces variation in offspring giving it a survival advantage if the environment changes

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

Give a disadvantage of sexual reproduction

A

need 2 parents, more energy is needed, slower process and fewer offspring produced

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

Give an advantage of asexual reproduction

A

Only need one parent, less energy is needed (more energy efficient), faster than sexual reproduction

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

Give a disadvantage of asexual reproduction

A

No variation, therefore susceptible to environmental changes

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

How many chromosome pairs are found in human body cells?

A

23 pairs

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

How many chromosomes are found in human sex cells

A

23

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Chromosomes are found
in the nucleus
26
Chromosomes are made up from
DNA
27
Put the following in order of size starting with the smallest cell, gene, nucleus, chromosome
gene, chromosome, nucleus, cell
28
What are genes?
Short sections on DNA found on chromosomes - they code for a particular characteristic
29
How are mitosis and meiosis different?
Mitosis is used for growth and repair, meiosis makes gametes
30
How many times does the cell divide in meiosis?
twice
31
How are the cells produced different from the parent cell in meiosis
they have half the chromosome number
32
How many cells are produced at the end of meiosis?
4
33
How many cells are produced at the end of mitosis?
2
34
At fertilisation what happens to the chromosome number?
It doubles and chromosome number is restored.
35
In the first step in meiosis what has to happen?
DNA/chromosomes copy/replicate themselves
36
Are the cells produced at the end of meiosis genetically identical or genetically different?
genetically different
37
During fertilisation what happens?
egg and sperm cell fuse together
38
Following fertilisation, what cell is made?
Zygote (fertilised egg)
39
What happens to the the fertilsed egg made following fertilisation?
It will divide by mitosis, cell number will increase to form an embryo and then eventually a foetus
40
What makes an embyro and a foetus different?
A embryo contains unspecialised cells, a foetus contains cells that have begun to specialise - they have differentiated.
41
What does differentiation mean?
When cells (in an embryo) begin to specialise
42
Give an example of a specialised cell
muscle, red blood cell, nerve
43
What is the genome?
It describes all of the genetic material that an organism has
44
Describe the structure of DNA
Double helix
45
Where is your DNA found?
In the nucleus in the form of chromosomes
46
How are genes and proteins linked together?
genes (code for characteristics) code for a sequence of amino acids that make a protein
47
Why is studying the genome important?
Search and study genes that cause disease, then try and treat the disease
48
TRIPLE DNA is a polymer made from 4 different nucleotides - what are nucleotides made from?
base, sugar and phosphate
49
TRIPLE Name the bases found in DNA
A, T, G and C
50
TRIPLE Which bases pair together?
AT and GC
51
TRIPLE How do the bases code particular amino acid sequence?
Sequence of bases grouped into 3s, every 3 bases codes for a specific amino acid
52
TRIPLE What do the order of the bases in DNA detemermine?
The order of the amino acids that make up the protein
53
TRIPLE In a long DNA molecule how are the sugar and phosphate arranged?
alternating
54
TRIPLE Which part of the nucleotide is the base attached to?
the sugar
55
A DNA polymer is made up of...
repeating nucleotide units/monomers
56
Define phenotype
outward appearance
57
define genotype
combination of alleles
58
Where are proteins synthesised?
ribosomes
59
TRIPLE When a protein in synthesised using DNA what carries the message to the ribosomes
template - mRNA
60
TRIPLE what molecule brings in specific amino acids according to the template to make a protein?
carrier molecules (tRNA)
61
TRIPLE When protein synthesis is complete what happens to the synthesised protein?
It folds up into a unique shape
62
What types of jobs can proteins have?
enzymes, hormones, structural proteins e.g. collagen
63
TRIPLE What is a mutation?
A change in the base sequence of DNA
64
TRIPLE what effect can mutations in DNA have on proteins?
Some may have no effect, others may completely alter the protein e.g. an enzyme no longer fits its substrate
65
TRIPLE Which parts of the DNA molecule DO NOT code for proteins?
Non-coding sections
66
TRIPLE What role can these non-coding portions have?
They can switch genes on or off
67
Of the 23 pairs of chromosomes in a body cell, how many control characteristics only?
22
68
The 23 rd pair of chromosomes is called the sex chromosomes, what they in females and males?
females - XX | males XY
69
Name a genetic disorder that is inherited
cystic fibrosis or polydactyl
70
What is polydactyl?
Having extra digits
71
What is polydactyl caused by?
A dominant allele
72
What is cystic fibrosis?
A disorder of the cell membranes
73
What is cystic fibrosis caused by?
A recessive allele
74
Name characteristic caused by a SINGLE gene
tongue rolling, attached ear lobes
75
Name characteristics caused by MULTIPLE genes
eye colour, hair colour, height, nose shape
76
What is a dominant allele?
where only one copy of the allele is required to express that trait -this allele is always expressed if present
77
What is a recessive allele?
where two copies are required to express that trait, its not expressed in presence of a dominant allele
78
What does homozygous mean?
Where you have two copies of the SAME allele for a given characteristic e.g. BB, bb
79
What does heterozygous mean?
Where you have 2 different copies of an allele for a given characteristic e.g. Bb
80
What is an allele?
A different version of the same gene e.g. blue eyed allele, green eyed allele, brown eyed allele
81
What are enzymes?
Proteins that are biological catalysts
82
What are hormones?
Chemical messengers that travel in the blood stream to a target organ
83
TRIPLE: What is mRNA
a molecule that carries the DNA code to the ribosomes from the nucleus
84
TRIPLE: When do mutations occur
randomly
85
TRIPLE: When can mutation rate be increased?
exposure to UV, chemical carcinogens, radiation
86
TRIPLE: A mutation changes the DNA base sequence of a gene - what does this create?
a different version of the gene - a new allele
87
TRIPLE: Give some examples of mutations
insertion, deletion and substitution
88
Do gametes have one or two copies of each chromosome?
one
89
What are the chances of have a pregnant lady have a boy?
50%
90
What sex chromosome do you find in a sperm?
X or a Y
91
What sex chromosome do you find in an egg cell?
X only
92
What sex determines the sex of the child?
Father - you will always receive an X from mum and then X OR Y from dad
93
How could you determine whether a pregnant woman was carrying a child with a genetic disorder?
embryo screening
94
Why might people be against embryo screening?
its expensive, may lead to designer babies and all parents wanting to screen embryos and pick the most desirable
95
Why are people for embryo screening?
stops suffering treating disorders can be expensive there are laws to stop it going too far

SHHS - Science - AQA Biology Trilogy (37 decks)

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