Exam 2- Alternation of generations
Microspore and Megaspore
What are the two types of Heterosporous?
Isomorphic and Heteromorphic
What are the two types of alternation of generations?
The multicellular diploid (2N) structure (sporophyte) produces haploid (N) spores through meiosis
What comes first in the cycle?
Two gametes join through fertilization and form a multicellular diploid sporophyte through mitosis
What comes last in the cycle?
Each spore develops int he multicellular haploid (N) structure (gametophyte) through mitosis
What comes second in the cycle?
The gametophytes produce haploid gametes through mitosis
What comes third in the cycle?
- phylum Phaeophyta (brown algae) of kingdom Stramenopila - kingdom Rhodophyte (red algae) - kingdom Chlorophyta (green algae)
Where does alternation of generations occur?
Homosporous
Where one type of gamete is produced
Heterosporous
Where spore produces either a male or a female gametophyte
a) isomorphic: N & 2N have similar forms, Heteromorphic: N &2N have distinct forms
Which of the following most accurately defines isomorphic and heteromorphic forms? a) isomorphic: N & 2N have similar forms, Heteromorphic: N &2N have distinct forms b) isomorphic: N & 2N have distinct forms, Heteromorphic: N &2N have similar forms c) isomorphic: 2N forms that are similar, Heteromorphic: 2N forms that are distinct d) isomorphic: N forms that are similar, Heteromorphic: N forms that are distinct
Heteromorphic
refers to a diploid and haploid form that are structurally distinct
Isomorphic
refers to a diploid and haploid formt hat are structurally similar
Megaspore
A haploid structure that develops into the famed gametophyte, which then produces eggs
Microspore
A haploid structure that develops into the male gametophyte, which then produces sperm
Alternation of generations
Alternation between multicellular haploid (N) and multicellular diploid (2N) life stages
d) recombination of genetic material between paternal and maternal chromosomes occurs
Crossing over increases genetic variation because? a) homologous chromosomes align independently on the metaphase place b) there are 2^23 different combinations of chromosomes that can occur c) alignment of each chromosome pair in independent of one another and completely random d) recombination of genetic material between paternal and maternal chromosomes occurs
a) 40%
In a population of algae, 40% of the gametophytes show a resistance to a certain toxin. What is the expected frequency of sporophytes showing resistance to the toxin? a) 40% b) 14% c) 16% d) 100%
b) haploid spores; haploid gametes
In alternation of generations, the sporophyte produces ____, and the gametophyte produces ____. a) diploid spores; haploid gametes b) haploid spores; haploid gametes c) haploid gametes; haploid spores d) diploid gametes; haploid spores
Homosporous or Heterosporous
Life cycles can be ____
c) Meiosis; mitosis
Spores are produced through ____, and gametes are produced through ____. a) meiosis; fertilization b) mitosis; meiosis c) meiosis, mitosis d) mitosis; fertilization
