Предмет: Биология, автор: marina191999

опишите процесс размножения и развития лягушки. Укажите сходство и размножение земноводных и рыб.

Ответы

Автор ответа: borneo1

Процесс размножения лягушки

Оплодотворение у лягушек внешнее. После того, как самка выбрала самца, они приступают к поиску места для икры. Самец обнимает самку (способ захвата зависит от вида лягушек), и самка мечет икру в воду. В это время самец оплодотворяет икру, часто придерживая ее лапками.

Процесс развития лягушки.

Из оплодотворенной икры вылупляется головастик. Он похож на маленькую рыбку. У него есть тело, внешние жабры, боковая линия, двухкамерное сердце, хвост и нет конечностей. По мере взросления у головастика вырастают задние, потом передние лапки, отваливается хвост. Одновременно происходят изменения во внутреннем строении исчезают жабры, исчезает боковая линия, развиваются легкие, трехкамерное сердце, развивается второй круг кровообращения. Из растительноядного головастик постепенно превращается в хищника.

Укажите сходство в размножение земноводных и рыб.

1. Внешнее оплодотворение у рыб и земноводных

2. И земноводные и рыбы мечут икру

3. Размножение происходит в водной среде

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