Def Test 3 Flashcards Preview

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Flashcards in Def Test 3 Deck (30):
1

Perianth

Comprises of the Corolla and calyx

2

Corolla

Ring of petals in angiosperms

3

Receptacle

Support all floral parts. Forms part of the fruit (along with the ovary) in the apple.

4

Pedicle

Flower stalk

5

Self-pollination

Transfer of pollen from the anther to the stigma of the same plant

6

Cross-pollination

Transfer of pollen from the anther to the stigma of a different plant

7

Pollen

Capsule that houses and protects the (male) microsporangium

8

Microsporangium

Make plant gamete

9

Macrosporangium

Female plant gametes (ovule in angiosperms)

10

Pollinator

Animal vector that transfers pollen from the anther to the stigma

11

Morphological divergence

The development of different structural characteristics in organisms from the same ancestor

12

Comparative anatomy

Comparing anatomical structures between different organisms

13

Evolution

Change in the genetic composition of a population

14

Genotype

Genetic composition/ make-up of an organism

15

Population size

The total number of organisms (of the same species) in a specific area at a specific time

16

Census

Direct method of determine population size, where every individual organism of a specific species is counted

17

Sessile

Unable to move / change location

18

Population density

The number of individuals of a species per unit area

19

Environmental resistance

Total number of limiting factors that stop a population from reproducing at a maximum rate / limits population growth

20

Tolerance level

The maximum and minimum range of a limiting factor, outside of which, an organism cant survive

21

Carrying capacity

The maximum number of individuals of a species that an environment can support without damage

22

Density dependent factors

Limit the population growth by exerting stronger effects on the morality as the population grows

23

Density independent factors

Negatively affect the natality and morality rates, irrespective of the population size

24

Meiosis

A type of nuclear division that produces daughter cells that half the chromosomal number of the parent cell.

25

Crossing over / chiasmata

Process by which homologous chromosomes lie in synapse and exchange genes / DNA between their chromatids

26

Chiasma

The pint at which the homologous chromosomes are crossing

27

Sister chromatids

Two identical chromatids that are connected by a centromere to form a replicated chromosome

28

Bivalent

Structure formed in meiosis when 2 homologous chromosomes lie next to each other in a synaptic state

29

Non-disjunction

The failure of chromosomes to separate correctly during either of the neurotic divisions

30

Syndrome

A collection of symptoms that indicate a specific disorder