Prelim Unit Two

Question 1

Stem cells

Answer 1

Unspecialised cells
Used for growth and repair
Come from embryo

Question 2

Mitosis

Answer 2

pairs of chromatids become visible
Line up at equator
Pulled apart by spindle fiber to form two new nuclei
Cytoplasm spilts to form two daughter cells

Question 3

Specialised cells

Answer 3

Sperm
Red blood cell
Muscle cell

Question 4

Parts of NS

Answer 4

Brain CNS
Spinal cord CNS
Nerves

Question 5

NS made up of

Answer 5

Neurons

Question 6

Parts of brain

Answer 6

Cerebrum
Cerebellum
Medulla

Question 7

Cerebrum

Answer 7

Responsible for thoughts consciousness reasoning and emotions

Question 8

Cerebellum

Answer 8

Balance and coordination

Question 9

Medulla

Answer 9

Breathing and heart rate

Question 10

Receptors

Answer 10

Generate electrical impulses in response to stimuli

Question 11

Electrical impulses

Answer 11

Carry messages along sensory neurons in the CNS

In inter neurons carry messages to motor neurons

Question 12

Motor neurons

Answer 12

Electrical impulses carry messages to effectors and brings response

Question 13

Synapse

Answer 13

Narrow gap between neurons

Chemicals released into it to allow electrical impulse to be generated in next neuron

Question 14

Reflex

Answer 14

Protect the body from harm

Rapid actions that don’t require processing from brain

Question 15

Reflex arc

Answer 15

The group of neurons involved with the structure and function of a reflex

Question 16

Gametes

Answer 16

Sex cells
Haploid
Either make or female

Question 17

Flowers

Answer 17

MALE GAMETES
inside pollen grains and made in anthers
FEMALE GAMETES
inside ovules and made in ovaries

Question 18

Humans

Answer 18

MALE GAMETES 
sperm cells produced in testes
Sperm very small can swim
FEMALE GAMETES 
egg cells produced in ovaries 
Larger and have food supply

Question 19

Fertilisation

Answer 19

Fusion of two haploid nucleis to form diploid zygote that divides to become embryo

Question 20

Haploid

Answer 20

Single set of chromosomes

Question 21

Diploid

Answer 21

Double set of chromosomes

Question 22

Zygote

Answer 22

Fertilised egg

Question 23

Variation

Answer 23

Differences in species

Combining two genes from two parents adds to variation

Question 24

Discrete variation

Answer 24

Clear cut difference
Shows discontinuous pattern
Involves single gene inheritance

Question 25

Polygenic

Answer 25

Different alleles of different genes involved | Continuous variation

Question 26

Polygenic inheritance

Answer 26

Shows variation of values between minimum and a maximum

Question 27

Phenotype

Answer 27

Outward appearances of characteristic

Question 28

Genotype

Answer 28

Symbols of phenotype

Question 29

Recessive

Answer 29

Allele of gene that only shows in phenotype if it’s homozygous

Question 30

Alleles

Answer 30

Type of gene

Question 31

Homozygous

Answer 31

Same allele from each parent

Question 32

Heterozygous

Answer 32

Different alleles from each parent

Question 33

Monohybrid cross

Answer 33

Made to study the inheritance

Question 34

Punnet squares

Answer 34

Used to explain inheritance

Question 35

Family tree diagrams

Answer 35

Used to identify genotypes