Biology <3

Question 1

Which are examples of discontinuous variation?

Answer 1

Blood group + Eye colour

Question 2

Which are examples of continuous variation?

Answer 2

Weight + Height

Question 3

What is mutation?

Answer 3

A change in the base sequence of DNA. This can sometimes cause a new allele to be created.

Question 4

What are the sex cells in males and females?

Answer 4

Male : XY Female : XX

Question 5

What is a homozygous genotype?

Answer 5

The same alleles e.g. BB bb

Question 6

Describe the amount and type of cells created in meiosis.

Answer 6

4 Haploid cells.

Question 7

Which type of cell division produces gametes?

Answer 7

Meiosis.

Question 8

What is an allele?

Answer 8

A version of a gene.

Question 9

Describe the amount and type of cells created in mitosis.

Answer 9

2 Diploid cells.

Question 10

What is meant by the term genome?

Answer 10

The entire genetic material of an organism.

Question 11

What are the 4 stages of the cell cycle?

Answer 11

G1 : Growth, S : DNA replication, G2 : Growth, M : Mitosis

Question 12

What is meant by a heterozygous genotype

Answer 12

2 different alleles of the same gene e.g. Bb

Question 13

What are the steps in natural selection?

Answer 13

1. Variation ( caused by mutation )
2. Better adapted organisms survive and reproduce
3. Pass on advantageous genes to offspring
4. Repeat over many generations so advantageous allele becomes more common

Question 14

What is evolution?

Answer 14

The gradual change of species overtime.

Question 15

What is a species?

Answer 15

A group of small similar organisms that can breed together to produce fertile offspring.

Question 16

What is phylogenetics?

Answer 16

The study of evolutionary relationships based on molecular studies.

Question 17

What can provide evidence for evolution?

Answer 17

Fossil records, antibiotic resistance in bacteria and comparing DNA of species.

Question 18

What is artificial classification?

Answer 18

Classification using observable characteristics such as ‘ flower has long yellow petals ‘

Question 19

What is natural classification?

Answer 19

Classification using DNA sequencing to show evolutionary links based on common ancestors.

Question 20

What is the order of the 7 taxonomic levels?

Answer 20

Kingdom, phylum, class, order, family, genus, species

Question 21

Who developed the theory of natural selection?

Answer 21

Charles Darwin.

Question 22

Why would photosynthetic rate decrease at higher temperatures?

Answer 22

Enzymes are denatured which means the active site is no longer matches the substrate.

Question 23

Is photosynthesis endothermic or exothermic?

Answer 23

Endothermic.

Question 24

Name three uses of glucose in plants.

Answer 24

Respiration , Stored as starch , Making complex molecules.

Question 25

Name and describe the two stages of photosynthesis.

Answer 25

1. Light dependent - splits water using light.
2. Light independent - hydrogen ions react with CO2 to form glucose.

Question 26

Describe the three steps needed to test a leaf for starch.

Answer 26

1. Boil to denature enzymes
2. Add ethanol to break down cell wall of each cell
3. Add iodine if it turns black starch is present

Question 27

Name the subcellular organelle where photosynthesis occurs.

Answer 27

Chloroplast

Question 28

State three factors that can limit the rate of photosynthesis?

Answer 28

Temperature , Light intensity , Carbon dioxide concentration