4.6.1 Reproduction (will come up) P2 Flashcards

1
Q

What is sexual reproduction

A

Type of reproduction
Involves the production of gametes by meiosis
A gamete from each parent fuses to form a zygote
Genetic information from each gamete is mixed so the resulting zygote is unique

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

What are gametes

A
Sex cells (sperm + egg, pollen + egg)
Haploid cells (half the number of chromosomes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is meiosis

A

Form of cell division involved in the formation of gametes in reproductive organs
Chromosome number is halved
Involves 2 divisions

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

What must occur prior to meiosis

A

Interphase - copies of genetic information are made during this process

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

What happens during the first stage of meiosis

A

Chromosome pairs line up along the cell equator
The pair of chromosomes are separated and move to opposite poles of the cell
Chromosome number is halved

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

What happens during the second stage of meiosis

A

Chromosomes line up along the centre of cell
The chromatids are separated and move to opposite poles of the cell
Four unique haploid gametes are produced

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

Why is meiosis important for sexual reproduction

A

It increases genetic variation

It ensures that the zygote formed at fertilisation is diploid

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

Describe fertilisation and its resulting outcome

A

Gametes join together to restore the normal number of chromosomes and the new cell then divides by mitosis
As the embryo develops, cells differentiate

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

What is asexual reproduction

A

Involved mitosis only
Produces genetically identical daughter cells
Asexual reproduction involves only one parent and no fusion of gametes.

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

What is DNA

A

A double-stranded polymer of nucleotides, wound to form a double helix

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

Define genome

A

The entire genetic material of an organism

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

Why is understanding the human genome important

A

Important for the development of medicine in the future

Searching for genes linked to different types of disease
Understanding and treating inherited disorders
Tracing human migration patterns from the past

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

What is a chromosome

A

A long, coiled molecule of DNA that carries genetic information in the form of genes

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

How many chromosomes do human body cells have

A

46 (23 pairs)

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

How many chromosomes do human gametes have

A

23 chromosomes

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

Define gene

A

A small section of DNA that codes for a specific sequence of amino acids which undergo polymerisation to form a protein

17
Q

What are the monomers of DNA

A

Nucleotides

18
Q

What are DNA nucleotides made up off

A

Sugar
Phosphate
1 of the 4 bases

19
Q

State the full names of the four bases found in nucleotides

A

Adenine Thymine

Cytosine Guanine

20
Q

How nucleotides interact to form a molecule of DNA

A

Sugar and phosphate molecules join to form a sugar-phosphate backbone in each DNA strand
Base connected to each sugar
Complementary base pairs (AT, CG) joined by weak hydrogen bonds

21
Q

How a gene codes for a protein

A

A sequence of 3 bases in a gene forms a triplet
Each triplet codes for an amino acid
The order of amino acids determines the structure and function of protein formed

22
Q

Why is the ‘folding’ of amino acids important in proteins such as enzymes

A

The folding determines the shape of the active site which must be highly specific to the shape of its substrate

23
Q

What is protein synthesis

A

The formation of a protein from a gene

24
Q

What are the 2 stages of protein synthesis

A

Transcription

Translation

25
Q

What does transcription involve

A

The formation of mRNA from a DNA template

26
Q

Outline transcription

A
  1. DNA double helix unwinds
  2. RNA polymerase binds to a specific base sequence of non-coding DNA in front of a gene and moves along the DNA strand
  3. RNA polymerase joins free RNA nucleotides to complementary bases on the coding DNA strand
  4. mRNA formation complete. mRNA detaches and leaves the nucleus
27
Q

What does translation involve

A

A ribosome joins amino acids in a specific order dictated by mRNA to form a protein

28
Q

Outline translation

A
  1. mRNA attaches to a ribosome
  2. ribosome reads the mRNA bases in triplets. Each triplet codes for 1 amino acid which is brought to the ribosome by a tRNA molecule
  3. A polypeptide chain is formed from the sequence of amino acids which join together