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Evgen [1.6K]
4 years ago
13

At one time, Chondrichthyes were thought to have split off from other vertebrates before the evolution of bone. Now we have conc

luded that the Chondrichthyes split off after the evolution of bone had started. This change demonstrate
Biology
1 answer:
Goshia [24]4 years ago
8 0

Answer:

Chondrichthyes Class of vertebrate animals characterized by a cartilaginous endoskeleton, a skin covered by placoid scales, the structure of their fin rays, and the absence of a bony operculum, lungs, and swim bladder. It includes the subclasses Elasmobranchii (sharks, rays) and Holocephali (ghostfish).

Explanation:

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What is the best explanation for the process of transpiration in plants?​
ra1l [238]

Explanation:

Transpiration, plant breathing, is when plants absorbs water from the roots using the xylem and phloem and takes them to the leaves where they exit as water vapour via the stomata (tiny openings). Through transpiration plants are able to cool themselves and produce their own food using the process of photosynthesis.

6 0
4 years ago
providing examples explain how sexual reproduction in plants has evolved to become less dependent on water
Mars2501 [29]

The Gymnosperms and Angiosperms are groups of plants with seed, which means that they don’ t necessary acquire water for fertilization. These groups have made adaptations for sexual reproduction on dry land.

1) Gymnosperms (plants with the seeds are not enclosed in an ovary) have developed over the course of its evolution, structures that solved the main limitations present in the Pteridophytes in relation to sexual reproduction, in the terrestrial environment. The main changes that happened as an evolutionary adaptation to dry land are those on the seeds and pollen. The advantages of the seeds are: the storage tissue which sustains growth and a protective coat of the seeds. Seed is enveloped with the layers of hardened tissue which prevents desiccation. This is what frees reproduction from the need for a constant supply of water. <span>The sperm (male gamete) of gymnosperms</span> is enclosed in a pollen grain. Thi structure is protected from desiccation and can reach the female organs without dependence on water. Gymnosperms also developed structures called cupules to enclose and protect the ovule (the female gametophyte) which will develop into a seed upon fertilization.

 

2) Angiosperms are a group of plants which protect their seeds within an ovary called a fruit. Angiosperms have special evolutionary adaptations. For example, they produce their gametes in separate organs, usually in a flower, so the fertilization and embryo development takes place inside an anatomical structure. That provides a stable system of sexual reproduction largely sheltered from environmental fluctuations like water need.

7 0
4 years ago
Read 2 more answers
How many months is 243 days
Fed [463]
243/30=8.1  
I do believe this is the answer you are looking for
8 0
4 years ago
According to the principle of intrinsic fitness (the representation of your genes in your relatives), which of the following str
MakcuM [25]

Answer:

Option A

Explanation:

As per the principle of intrinsic fitness, a person likes to work for his/her inner satisfaction driven by motivation within him/herself.

Thus, a young bird which feels an urge to produce chicks by mating each year will ultimately go outside to find his/her mate on their own and will produce chick every year. In an intrinsic behaviour the rewards achieved are internally self satisfying and thus a person need no assistance in achieving them on their own.

Thus, option A is correct.

6 0
3 years ago
How does the accuracy of a calculation depend on the number of significant figures in the measurement used to do the calculation
AleksandrR [38]

In general, a calculated answer cannot be more precise than the least precise measurement from which it was calculated

5 0
4 years ago
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