B13- Reproduction

Question 1

2 types of reproduction

Answer 1

Asexual and sexual

Question 2

Asexual
Parent?
Division?
Genetic material?
Variation?
Examples?

Answer 2

One parent
Mitosis
No mixing of genetic information (clones)
No variation
Fungi, bacteria, starfish

Question 3

Sexual
Parent?
Division?
Genetic material?
Variation?
Examples of cells?

Answer 3

Male and female gametes fuse together to form a zygote
Meiosis
Inherit genetic information from both parents
More variation
Animals, sperm and egg cell. Plants, pollen and egg cells

Question 4

Meiosis
Forms?
3 steps?

Answer 4

Gametes (haploid cells)
1. Parent cell has 46 chromosomes (2 sets)
2. Genetic info is copied so there are 92 chromosomes (4 sets)
3. Cell quickly divides twice, forming 4 gametes each with 23 chromosomes (1 set)

Question 5

Diploid cell chromosomes?
Haploid cell chromosomes?

Answer 5

46 chromosomes

23 chromosomes

Question 6

How is variation achieved in meiosis?

Answer 6

Each gamete is genetically different. When the gametes fuse, a set of chromosomes comes from each parent. The genes in the new zygote will contain different forms of the alleles (genes) from each parent.

Question 7

Asexual reprod
Ads & dis?

Answer 7

Ads- time and energy efficient as no mates required. Quickly produces large no of offspring
Dis- limited variation, if one can’t survive, none can

Question 8

Sexual reprod
Ads & dis?

Answer 8

Ads- produces variation, better for natural selection. Used by humans for selective breeding for food production
Dis- takes time and energy to find mates. Slower than asexual

Question 9

Reproduction in fungi
Most common type?
How are both types used?

Answer 9

Asexual
Asexual= produces spores by mitosis, stable conditions
Sexual= poor conditions, forms haploid spores with variation

Question 10

Reproduction in plants
How are both types used?

Answer 10

Asexual= plant grows due to mitosis, e.g strawberry runners and bulbs
Sexual= pollen from one flower reaches another by animals and insects, pollen fuses w egg cell

Question 11

Reproduction in malaria parasites
How are both types used?

Answer 11

Asexual= when inside human liver and blood cells
Sexual= when inside female mosquitos due to a temp change when the mosquito bites a human

Question 12

What is a genome?
What was the project called and what did it involve?
When did it happen?

Answer 12

An organism’s entire set of genetic material
The Human Genome Project-> when the entire human genome was mapped out and sequenced
from 1990 to 2003

Question 13

Structure of DNA

Answer 13

A polymer made up of repeating nucleotides to form a double helix shape

Question 14

Advantages of the human genome project?

Answer 14

-Understand inherited disorders
-Understand human evolution and history
-Understand relationships between organisms

Question 15

What is a gene and what does it do and why?

Answer 15

A small section of DNA
Codes for a sequence of amino acids
In order to make a specific protein

Question 16

What is a nucleotide made up of?
What are the 4 bases?
What is each base attached to?

Answer 16

A sugar, a base and a phosphate
A T C G
Each attached to a sugar

Question 17

What groups are nucleotides in?
What is needed to code for one amino acid?
What changes the type of protein made?

Answer 17

Nucleotides are grouped in 3
3 bases code for 1 amino acid
The order of bases

Question 18

What bases are always together?

Answer 18

C and G
A and T

Question 19

RNA
What is it?
Key feature?
Base changes?

Answer 19

A copy of DNA
Single stranded
U instead of T
U pairs with A

Question 20

2 stages of protein synthesis

Answer 20

1. Copying the DNA
2. Making the protein, leaves nucleus goes to ribosome

Question 21

Protein synthesis
How is DNA copied in protein synthesis?

How is the protein made?

Answer 21

DNA’s double helix unzips. RNA is made and leaves the nucleus.

RNA leaves nucleus, binds to ribosome. Cytoplasm has ‘carrier molecules’ that bind to RNA and bring specific amino acids until the protein is formed. Once chain is complete, the protein detaches from carrier molecules and folds up, carrier molecules detach from RNA.

Question 22

Mutations def?

Answer 22

Random changes that can occur in an organism’s DNA