Question

1. In Chapter 13, 14 and 15 we explore the diversity of organisms, including a looks into adaptations that enable them to thrive in their respective habitats. Respond to the following two prompts relating to these three chapters: Compare and contrast reproduction methods in TWO (2) of the following groups – in what ways are they similar and different? Seedless plants Fungi Protists Frogs Sponges In order to transition to a life on land, certain adaptations were required to help organisms deal with a world where they weren’t surrounded by water. Water helps organisms to reproduce easily (by just releasing egg and sperm into the water) and keeps the organism hydrated. Provide examples of adaptations that made it possible for two (2) types of organisms to a) reproduce effectively and b) prevent desiccation (drying out). You may select any two terrestrial (land) organisms that strike your fancy.

Answer 1

in frogs according to speceies both internal and external reproduction take place ,but no asexual reproduction . but not asexual reproduction

at the breeding site the female releases her eggs and male coveres them with sperms tadpoles develops and it metamorphos in to adult . water is needed for its reproduction . the collection of eggs is known as frog spawn .the gelatinous jelly around embryos provide support ,allows passage of o2 ,co2 and ammonia .it absorbes moisture and swells on contact with water . the larvae emerges from this fertilized egg is tadpole .the spawning may triggered by enviournmental signals such as water ,temperature . in terrestrial organisms internal fertilization is more common . usually the male deposit sperm in the enviournment in a protective structure female picks up it to deposit in her reproductive tract . the offspring develops in three different ways

oviparity fertilized egg laid out the female body and develop there receiving nutrition from yolk example birds and amphibians the calcium shells prevent dessication

ovoviviparity fertilized egg retained in females body until they hatch inside of her example lizzard

viviparous young one born alive example mammals

sponges reproduction - sponges reproduce sexually and asexually . after fertilization larva released in to water it flows around for few days and then sticks to a solid . sponges also reproduce by budding . sponges are hermophrodite but produce one type of gamate at one time .the water current system in sponges help to disperse gamate and larvae

fungi - asexual reproduction by spores , budding and fragmentation   sexual reproduction is by mating of positive and negative hyphae

water is essential for fungal spore germination in addition to water they need a physical or chemical activator

protists reproduce asexually by binaryfission , budding and by conjugation

in seedless plants like ferns reproduction by sporulation or from haploid spores new plants originate . here alternation of generation can be seen dipploid sporophytic stage alternates with haploid gametophytic stage . gametophyte is a plant produces gamates by mitosis . sporophytic plant produce spores by meosis and from this spores gametophye plant develops with archegonium and antheridium structure , here the male gamates are carried to archigonium with the help of rain water fertilization take place and zygote develops in to sporophytic diploid plant

the adaptation in terrestrial animals are internal sexual reproduction which prevent dehydration of sperm and egg

presence of amniotic sac which provide a watery enviornment for development of embryo

presence of eggshell prevent dessication of embryo

presence of placenta for exchange of nutrition

b adaptation against dessication 1 cryptobiosis the state of organism when it shows no visible sign of life and its metabolic activity hardly measurable found in viruses , fungi seeds of higher plant

desert animals have fewer sweat glands

desert plants have thick waxy skin to reduce water loss

c a means of reproducing and providing for early embryonic development out of water . internal fertilization protect the egg and sperm from drying and the egg develops in amniotic fluid to accomplish an aquatic enviornment

in placental mammals the young one born in a more advanced stage