Exam 2 Flashcards Preview

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Flashcards in Exam 2 Deck (29):
1

Fertilization

Joining of gametes (sperm and egg)

2

Gamete

Egg and sperm

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Zygote

Single cell of the fused gametes

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Haploid

Has half the number of chromosomes (23)

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Diploid

Has the normal amount of chromosomes (46)

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Binary Fission

Single called organisms that divide into two to make two identical offspring

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Genes

Units of inheritance from DNA that encode proteins

8

Chromatin

DNA and proteins that form a condensed package

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Centromere

Holds two sister chromatids together

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Sister Chromatids

Two copies of the same chromatin joined together at the centromere

11

Homologous Pair

23 pairs, one of each pair is taken by one parent

12

Sex Chromosomes

X and Y chromoses that determine the sex of the offspring
XY- boy
XX- girl

13

Cytokinesis

Division of cytoplasm splitting of two cells

14

Interphase

G1- growth to enter S phase
S- synthesis of duplication of DNA
G2- growth to start mitosis or meiosis

15

Mitosis

Prophase- chromosome becomes visible and nuclear envelope disappears
Metaphase- chromosomes become attached to the spindle fibers
Anaphase- chromosomes move away from one another to opposite poles of the spindle
Telophase- chromatids move to opposite ends of the cell and two nuclei form

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Meiosis

Produces four gamete cells for sexual reproduction

17

Cell plates

In plant cells because of the cell wall. Plants divide their cytoplasm by making a call plate which is composed of membrane and cell wall materials

18

Crossing over

When homologous chromosomes pair, maternal and paternal chromosomes overlap ends of their sister chromatids and swap genetic information

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Character

An inherited feature that varies from one individual to another

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Trait

Variations in characters

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Allele

Different types of genes

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Homozygous

Both alleles from parents are the same

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Heterozygous

Both alleles rom parents are different

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Dominant

Allele that determines the organisms appearance

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Recessive

Allele that doesn't show

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Phenotype

Physical appearance of traits

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Genotype

Genetic appearance of the trait

28

Incomplete dominance

Occurs in heterozygous where both alleles blend together to make a phenotype
(Red and white make pink)

29

Codominance

Both alleles are present in the organisms phenotype (not blended) black and white make black and white spotted